It’s not the feed, organic, vegetarian, or anything else.
Each chicken is an individual. They will lay when they lay. There are some general breed tendencies but much more important is what their parents did. If someone selectively breeds chickens that start to lay early, then the odds are that their offspring will lay early. If someone selects breeders for other traits and early laying is not important, then the odds are the offspring will not start laying as early. Even saying that, when they start laying is very individual, but hatchery birds tend to be early rather than late.
Some people tend to think that each and every hatchery in the world is identical to all the others and turn out identical birds. That’s not the case. They have different business plans (that means they operate differently) and they have different people selecting their breeding birds. You can get quite different birds of the same breed from different hatcheries. I have. What you get from people that call themselves breeders can vary even more. It purely depends on what traits they are selecting for and their individual abilities in selecting the breeding birds.
14 hours of light is not a magic number for chickens. Some chickens near the equator never see 14 hours of daylight in their life, yet they lay really well and follow seasonal patterns. Don’t get me wrong. Light is important. But the importance is much more of the days getting longer or shorter, not so much the length of the daylight. There is nothing wrong with providing 14 hours of light per day if that is what suits your location and that is what you want to use. But there is nothing magic about it.
It’s too late for you, but if you had let the days naturally get shorter for a while, then started increasing the length of the days, you could have probably fooled them into thinking spring was here and it is time to start laying. Commercial laying operations do it that way. They don’t want their chickens to start laying real early, which their hybrids tend to do. They want them to get to a certain level of maturity so the eggs they lay are a little bigger which sell for more and their bodies are mature enough to handle the stress of laying those big eggs without damaging themselves. I personally don’t consider chickens starting to lay real early a huge benefit. I want eggs like everybody else but I want them mature enough that they are really ready. Yours are plenty old enough for that, by the way.
First year pullets often lay throughout the winter whether you provide extra light or not. I do not provide extra light. Normally if mine start laying in late summer or later they skip the molt the first year and lay straight on through until the next fall.
Last fall, I had some that started laying in the second week of December, right at the shortest days of the year and with the days still getting shorter. They were about 22 weeks old. But there were a few of them that waited until February and the days were getting noticeably longer before they started to lay.
This year I have some that I got from a breeder. The first one of those started laying at 30 weeks in the last week of November. The others have not started to lay. I processed two of them yesterday that I decided I was not going to keep. From looking at them inside, they were not anywhere close to laying.
I also hatched some of my own eggs. At 20 weeks, again in the last week of November, two started laying. I processed the other three yesterday. None of those three were even close to starting.
My thoughts on your specific situation. Decide what you are going to do with the light, then be consistent while doing it. Changing light all over the place is just likely to confuse them. It takes a while for their bodies to switch to laying mode. Be patient and give them time.
I see you have three breeds but I don’t know how many total you have. Each chicken is an individual and will follow its own schedule. The more you have, the more likely you are to get one that starts early. But that is just odds. There are no guarantees. I’ve had chickens from the same hatchery of the same breeds that were raised together under the same conditions where some started laying at 18 weeks and some started at 27 weeks in the middle of summer. You may have just gotten a bunch of the late starters. For some of them, the light is really important. For some, not so much.
My suggestion. Decide what you are going to do, then do it and be patient. It will happen when it happens.
